10个原生JavaScript技巧

1、原生JavaScript实现字符串长度截取

function cutstr(str, len) {    var temp;    var icount = 0;    var patrn = /[^\x00-\xff]/;    var strre = "";    for (var i = 0; i < str.length; i++) {        if (icount < len - 1) {            temp = str.substr(i, 1);            if (patrn.exec(temp) == null) {                icount = icount + 1            } else {                icount = icount + 2            }            strre += temp        } else {            break        }    }    return strre + "..."}

2、原生JavaScript获取域名主机

function getHost(url) {    var host = "null";    if(typeof url == "undefined"|| null == url) {        url = window.location.href;    }    var regex = /^\w+\:\/\/([^\/]*).*/;    var match = url.match(regex);    if(typeof match != "undefined" && null != match) {        host = match[1];    }    return host;}

3、原生JavaScript清除空格

String.prototype.trim = function() {    var reExtraSpace = /^\s*(.*?)\s+$/;    return this.replace(reExtraSpace, "$1")}

4、原生JavaScript替换全部

String.prototype.replaceAll = function(s1, s2) {    return this.replace(new RegExp(s1, "gm"), s2)}

5、原生JavaScript转义html标签

function HtmlEncode(text) {    return text.replace(/&/g, '&').replace(/\"/g, '"').replace(/</g, '<').replace(/>/g, '>')}

6、原生JavaScript还原html标签

function HtmlDecode(text) {    return text.replace(/&/g, '&').replace(/"/g, '\"').replace(/</g, '<').replace(/>/g, '>')}

7、原生JavaScript时间日期格式转换

Date.prototype.Format = function(formatStr) {    var str = formatStr;    var Week = ['日', '一', '二', '三', '四', '五', '六'];    str = str.replace(/yyyy|YYYY/, this.getFullYear());    str = str.replace(/yy|YY/, (this.getYear() % 100) > 9 ? (this.getYear() % 100).toString() : '0' + (this.getYear() % 100));    str = str.replace(/MM/, (this.getMonth() + 1) > 9 ? (this.getMonth() + 1).toString() : '0' + (this.getMonth() + 1));    str = str.replace(/M/g, (this.getMonth() + 1));    str = str.replace(/w|W/g, Week[this.getDay()]);    str = str.replace(/dd|DD/, this.getDate() > 9 ? this.getDate().toString() : '0' + this.getDate());    str = str.replace(/d|D/g, this.getDate());    str = str.replace(/hh|HH/, this.getHours() > 9 ? this.getHours().toString() : '0' + this.getHours());    str = str.replace(/h|H/g, this.getHours());    str = str.replace(/mm/, this.getMinutes() > 9 ? this.getMinutes().toString() : '0' + this.getMinutes());    str = str.replace(/m/g, this.getMinutes());    str = str.replace(/ss|SS/, this.getSeconds() > 9 ? this.getSeconds().toString() : '0' + this.getSeconds());    str = str.replace(/s|S/g, this.getSeconds());    return str}

8、原生JavaScript判断是否为数字类型

function isDigit(value) {    var patrn = /^[0-9]*$/;    if (patrn.exec(value) == null || value == "") {        return false    } else {        return true    }}

9、原生JavaScript设置cookie值

function setCookie(name, value, Hours) {    var d = new Date();    var offset = 8;    var utc = d.getTime() + (d.getTimezoneOffset() * 60000);    var nd = utc + (3600000 * offset);    var exp = new Date(nd);    exp.setTime(exp.getTime() + Hours * 60 * 60 * 1000);    document.cookie = name + "=" + escape(value) + ";path=/;expires=" + exp.toGMTString() + ";domain=x.com;"}

10、原生JavaScript获取cookie值

function getCookie(name) {    var arr = document.cookie.match(new RegExp("(^| )" + name + "=([^;]*)(;|$)"));    if (arr != null) return unescape(arr[2]);    return null}